I want your opinions: Brushless controller features

[circuit]

Hello. Interesting thread you have here.

I'm also thinking of building my own BLDC controller (150A, 60V maybe) one day and here is one of my thoughts:
These motor drive/regen controllers use PWM (better ones - SVM) for voltage leveling that is running at ~10kHz (just a wild guess, don't know exact frequency). Correct me if I'm wrong, but BLDC motor core is made of isolated electrotechnic steel plates, that are about 0.25mm in thickness. This is a type of plates that is used in low frequency (50/60Hz) transformers. Problem here is that high frequency pulses induct parasitic currents in these plates and a part of energy is wasted to heat.
I'm considering possibility to mount powerful LC filters for pulse filtering. Caps would be connected with motor's unused center of windings (in "star" interconnection types) or they could be unused at all. Inductors should be made of thick wire wound around ferrite core.
I currently own Cyclone 500W kit and now Crystalyte 5403 is already on the way. So I do not have a motor and controller to do some experimenting. My guess, if it would improve performance, it should be noticeable by measuring current at full speed with no load.

Any thoughts on that?

[grindz145]

Is this project still going? I am VERY interested in this as well. I hope there is still some interest. I think I may give it a try as well, but I am thinking about using an AVR chip instead... I have some experience with the PICs but the AVRs just give you more MIPS and then some. Any thoughts on using AVRs?

Also on the point of speed sensing for using 2 wheel drive: I don't think you might need a bunch more datapoints for the hall affect aka: an ABS ring in order to get an accurate enough speed in order to change the speed. I love the idea of this for snow riding to insure both wheels are moving simultaneously reminiscent of ROKON http://www.rokon.com/

Alot of great ideas and apparently some pretty good EEs:-D

[wrobinson0413]

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[ZapPat]

Just thought I would bump this to see if you have made any progress yet Pat

Well progress is slower than I would like, Wayne, but it's at least still moving along. It's funny that you posted yesterday, since I was also wondering yesterday what you were up to these days, and how your own controller project was doing?

I have been neglecting this thread I must admit - There are soooo many things I have to think about already, so I figured I would get my latest PCB revision finished up before doing an update here and answering posts. It turns out that there are many challenges to bringing an ebike controller to market, and I'm not just talking technical challenges! Just juggling time around with my limited ressources is a headache, since I cannot even think of hiring or contracting out certain tasks yet. I have tried to get some financial assitance from different governemental entities, but it seems like I am in a business situation where NO goverment programs apply. Being a new start-up AND working in a technical R&D field are not well looked at it seems. You either have to be selling something already and they will give you extra money for R&D, or come up with some conventionnal non-innovative business proposal and you can also get assitance for starting up. It gets me a quite peeved sometimes when I see so many brainless and almost pointless projects around here get HUGE subsidies, and I've done math on a few of these and I can assure you they often make no economic sense whatsover! Also, having no track record also makes any helpfull associations with other existing companies/individuals difficult. To make things worse, I live in a "techinicaly challenged" area, where the only projects that are encouraged are tourism, wood loging, fishing, agriculture and gigantic wind turbine farms. So locally there are practically no companies that could be potential associates as they don't understand what I'm working on. So I'll have to be very patient it seems, and spend much more of my own time doing the non-technical things I would rather have someone else do to help make this creation eventually ready for production. Well, that's enough non-tech talk, but I had to spout some of my frustration about this boring yet important aspect of this project!

I am really looking forward to trying my design out on the road, since so far I've only had it running in my lab. My last PCB design had a couple errors to fix and a number of things to change, so when the new revision is done I'll be able to finalise my firmware and go for a run at ~50V and ~100A... hopefully in a month or two max. I now have some great LiPos for high powered testing, and will have two NC hubs (front+back) to play with, so my bike will be ready for some kick-ass testing when the time comes. I'll post my initial controller feature set in before I hit the road with it, but only after I've sent my last PCB off for etching. I'll answer all the old posts here I've been neglecting... sorry guys! I haven't managed to clone myself yet...

Ciao!
Pat

[wrobinson0413]

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